What Causes Depression?

An estimated 6% of Australians suffer from depression at any given time[1]. It is characterized by feelings of sadness, lethargy, anxiousness, worthlessness, guilt and sleeplessness that last for weeks, months or years. Some sufferers may have trouble getting out of bed or finding joy in activities that they once took pride in. Depression is not only taxing on the body, it impacts our workplace performance and costs the medical system billions every year[2]. Depressed people are less productive at work and take more sick days; and depression can impact on other ailments such as arthritis and cardiovascular disease.

Treatment of depression becomes challenging when we can’t pinpoint the exact cause of it. This forces us to examine the old “nature/nurture” debate. In all likelihood, depression is caused by a combination of several factors – including genetic predisposition and learned behaviour. However, other factors may be relevant as well. A typical treatment of depression often combines medication and some form of talk therapy.

Demographics may also play a role in depression. According to a recent study published by Forbes, the USA and the Ukraine have the highest depression rates in the world (9.6 and 9.1%, respectively). This is astounding when compared to the .8% rate of depression in Nigeria[3]. Whether it is the availability of mental health treatment, the cohesiveness of its citizens or some other factor – where you live is definitely a factor in whether you suffer from depression or not. Age also factors in – with rates of depression dropping off significantly after the age of 60. It is interesting to note that high poverty rates do not correlate with high rates of depression.

Biology has been recognized as a major factor in depression for ages. The brains of the depressed have imbalances of certain neurotransmitters. At a very basic level, low levels of dopamine, norepinephrine and serotonin are correlated with depression and anxiety. Anti-depressant medication can be very effective in rebalancing these levels of neurotransmitters.

Hormones may also play a role in depression. Women are far more likely to suffer from depression and postnatal depression occurs in 10-15% of new mothers[4]. Women experience sadness when hormones are most elevated – such as during menstruation and childbirth.

Genetics may also play a role in certain cases of depression. If you have a biological relative (parent or sibling) with major depressive disorder, your chances of having depression are somewhat higher. Certain personality traits, which increase the chances of developing depression, may be genetically inherited. For example; if resiliency is inherited, you may be less likely to suffer from depression because you are better equipped to cope with difficult life changes.

Social factors – including both your social network and your social upbringing – play a huge role in depression. If you grew up in a home where you felt isolated and watched your parent suffer through mental health issues, you will be far more likely to suffer through the same. Similarly, if you have a weak social network and few trusted friends, you are more likely to succumb to sadness. It is therefore possible, according to some, to overcome a genetic and biological predisposition to depression with strong social support and an upbringing that encourages positive thinking and open communication.

In reality, all of these factors contribute to depression. While genetics alone may not lead to a depressive state, when those genetics are combined with biology, your particular demographic group and your social skills, you have a veritable “perfect storm” for depression. Treatment that addresses the multi-faceted nature of depression will have the best long-term outcome and result.